Use FS_CHMOD_FILE rather than an explicit 0644 in copy_dir() and _copy_dir().

This occurs when we can't copy a file. We chmod it and try again.

see #22704.


git-svn-id: https://develop.svn.wordpress.org/trunk@25793 602fd350-edb4-49c9-b593-d223f7449a82
Core Updates: Verify that all files we're about to copy are actually writable, when using the direct transport.

Once we begin to copy core files, all bets are off. This allows us to fail early when we'll otherwise need to stop midway through due to permissions issues, which is a particularly bad problem when only some files have permissions issues.

see #22704.


git-svn-id: https://develop.svn.wordpress.org/trunk@25794 602fd350-edb4-49c9-b593-d223f7449a82
3.7-beta2-25795


git-svn-id: https://develop.svn.wordpress.org/trunk@25795 602fd350-edb4-49c9-b593-d223f7449a82